An Open letter to Mark Bundick, NAR President

[AlexM]

If you check with your local fire department, they might be willing to donate an old siren. They work freat for getting peoples attention, and the worst they can say is no.

 

[wwattles]

<Rant>

Regarding the subject of test-only launches with only untried rockets, that's not exactly an option for many of us. In my county, we have a single launch field that is authorized for rocketry. We only get it for two four-hour sessions every month, and even that isn't every month. Any other flying of rockets within the area is prohibited by law, including Micromaxx launches. We have dozens of scout troops, YMCA groups, Big Brothers/Big Sisters, church groups, school groups, and just about any other type of youth organization who all are contacting our club trying to "piggyback" on our launch permit on both of our flying days. Taking away from either of them for "test only" simply isn't going to be possible. Also, private launches don't work because we aren't allowed to do them, and going out to the desert doesn't do any good if we don't have our own launch equipment. Most of my fellow club members don't. We pay club dues to pay for the launch site, the chapter membership, and the club equipment. I've got a cheapo Estes Electron Beam, and that's it.

Regarding the subject of people paying attention to the launches, I can't tell you how many times I've been out at launches and seen kids playing back behind the cars. Why? Because dad is launching, the kids are entertained, and they are well away from the rockets. There are rules against people consuming alcohol while preparing rockets, so that they can have their wits about them while they concentrate on making their rockets ready and safe. Having the kids around can only distract from that, so parents let the kids go have some safe fun well away from the rockets. If you were to try to mandate that all human beings, regardless of age, pay attention to any launch, you'd see the NAR memberships plummet, because parents would no longer be able to go to launches with their kids.

Regarding the RSO inspection, I couldn't imagine what it would be like to have the RSO take my painstakingly packed chute out of my rocket, unfurl it to check the harness, the connection points, the shrouds, the blanket/wadding/etc, and then say, "Okay, you're good. Go out to the pads." I'd look at him and say, "Not until you take 15 of YOUR minutes and repack this chute!" When I did my L1 and L2 flights, the RSO gave my rocket a VERY thorough check-over, but didn't pull it apart for inspecting the innards. He did, however, ask me very detailed questions about its construction. "What type of harness connection?" "How long a shock cord, and what type?" "How much noseweight and what kind?" "What size chute and what material?" "How many centering rings, what material, and what adhesive?" I would expect no less from a responsible RSO.

As for the ultimate responsibility, it lies with the rocketeer. Anyone who thinks otherwise hasn't looked at the NAR L2 exam recently. The RSO can only check the rocket, but the ultimate responsibility to ensure safe design and build is the rocketeer him/herself.

</Rant>

WW

 

[AlexM]

Originally posted by wwattles

Regarding the RSO inspection, I couldn't imagine what it would be like to have the RSO take my painstakingly packed chute out of my rocket, unfurl it to check the harness, the connection points, the shrouds, the blanket/wadding/etc, and then say, "Okay, you're good. Go out to the pads." I'd look at him and say, "Not until you take 15 of YOUR minutes and repack this chute!" When I did my L1 and L2 flights, the RSO gave my rocket a VERY thorough check-over, but didn't pull it apart for inspecting the innards. He did, however, ask me very detailed questions about its construction. "What type of harness connection?" "How long a shock cord, and what type?" "How much noseweight and what kind?" "What size chute and what material?" "How many centering rings, what material, and what adhesive?" I would expect no less from a responsible RSO.

As for the ultimate responsibility, it lies with the rocketeer. Anyone who thinks otherwise hasn't looked at the NAR L2 exam recently. The RSO can only check the rocket, but the ultimate responsibility to ensure safe design and build is the rocketeer him/herself.

</Rant>

WW

If you were referring to my post, what I meant was to check your rocket unprepped: no wadding, chutes unwrapped, shock cord out, etc. just so he could check on how sound your recovery system is.

If you weren't referring to my post, pretend you were so I don't feel stupid.

 

[BrnAgainRoc]

As far as the topic goes this can give the NAR/TRA BOD's something to look at and read.I agree with jim about rocksim. The program isnt perfect nor is any other program created in the world.But its a base for rocket creations and gives a considerable "quote" on what to expect from a rocket. Now i do believe if you're a rocketeer you should become VERY knowledgable on how to use barrowmans equation. Its on th elines of basica knowledge for most of us.Now as far as a siren for a heads-up call a basic airhorn bought at wal-mart is fine.I just got done purchasing one for launches after this past launch we had. After being the director of the entire launch for the first actual time i learned a serious amount of info from steve mashburn and steve burnette that ill be putting into effect asap.RSO's play a VERY serious role in every launch. If NAR/TRA created a check list we would follow it to the T.But as always we must cover ourselves fully from lawsuits and what not from spectators. And ive easily done this simply when a car comes in I greet them and show them where to park since no one knows the layout and at the same time we post a poster board size WARNING board.You cant miss it at all. All fliers are signing liability waivers at the same time of filling out flight cards basically saying they are 100% responsible for their actions and rockets actions, and in turn it has a place for them to put their guests names so we can keep a head count at the same time kep ourselves in the clear. Another measure we will be taking is a spectator line. If they arent there to fly they may not pass the line or they will forfeit their rights to be there and will be asked to leave immediately.Strict you may ask? yep sure am but we dont want people hurt and last thing we need is people that have no idea what a rocket is or how they work wondering around areas such as prep tents and RSO table. I have caught people breaking certain rules and in turn i bring it to their attention. Ive made it clear that if i seem like a strict person its cause i am and its in everyones best interest that iam like that. If no one points out whats being done wrong then where ever that person goes they may continue to do the same thing over and over again and one day something bad come of it.So i like to think iam doing my part in breaking the cycle and maybe preventing an accident later on. As far as pre-testing a rocket before i get to the main launch site is somewhat hard. In my case its easier for me than it is for others since we have a fairly large flying field i can make a call to the land owner and be launching 30 minutes later.But some dont have the chance to do so. So add a new line to the flight cards guys. Add the line saying

Maiden Flight: yes____ No_____

its that easy. Then when lining the launch up put all the maiden flight launches together and that will be your HEADS-UP launch time where everyone must be out on the spectator line and watching the rockets launch and paying attention.This will work great since it turns out most people at a launch has a short attention span.Also peple HAVE to listen to the Hosts of the launch or show them the way out and ask them to not return till they understand and can abide by all the rules. Iam not scared of doing it. Cause i know if i dont respect the R&R and something happens on the launchsite, we lose our field and if that happens id be a VERY upset person.So dont allow some disrespectful people to ruin your launch. The rules that we are searching for are the main rules we already have but no one enforces.Start being strict with the rules abide by the ones we have and you will see a HUGe impact on what goes on at the field.

 

[henry8minus1]

Originally posted by jflis
Just to chime in (been reading with interest).

There are many good ideas here and some not so good. Also, I am sure many good ideas missing. It's all a part of the process.

One suggestion/request/recommendation: Do not *require* rocksim data.

It sounds like a good idea, but it isn't for many reasons.

- I've seen designs identified as *stable* in rocksim actually be unstable or marginally stable
- The tool is too limiting (I am NOT saying it isn't *good*. It is a fine tool. But it is still too limiting). You could not, for example, sim the ACME spitfire. Nor, for that matter the Decaffeinator, the Drake, the Stingray, the Night Whisper, The Deuce's Wild, the Tres, etc, etc, etc. Limiting. Yes, you can *approximate* many of these designs, but it is just and "approximation" from a tool that isn't perfect in the first place. Limiting.
- Not everyone has it, has access to it, nor should be required to buy it. There is no requirement for me to be a NAR member to fly rockets at a NAR event. Nor is it a requirement to own rocksim, nor is it a requirement to belong to a NAR section (where a copy may be found).
- Not needed. 45+ years of rocketry supports this.

Just a pet peeve. Rocksim is a great tool, don't get me wrong. But it should not ever be a requirement to enjoy rocketry.

jim

Thanks, Jim you saved me some typing. Now all I have to say is I agree. One more thing, who is to make sure that the actual contruction matches the rkt file?

Jeff

 

[mike_bar]

Ditto, I agree...

 

[BrnAgainRoc]

Like its been said i agree and disagree with the Rocksim idea. But the way things are going and all the controversy thats being stirred up about RSO's and not being stable and what not its gonna lean towards having proof that its stable such as a rocksim file OR you learn barrowmans equation and do the math in front of them. Biggest test of all would be if you want to fly this rocket show me the equation right here. Everyone is asking for strict rules to make things safer but they dont understand their going ot bite off more than they can chew and in the end it will make going to a launch painstaking cause of al the crap you would have to go through just to launch a rocket. And whats worse is for those who bring 8-10 rockets like i do.I agree with allowing the RSO to check my rockets and to pull the tops off and check the safety measures such as recovery types and all.Then after he clears the rocket then i prep it at my tent.But when i have alot of rockets its going to be aggravating to have to go through long checks. Ive been trying to express enough that if we take all the safety measures we have now and actually enforce them we wont have any large safety issues. Its common sence to get everyone out of the little area if a rocket is going to come in balistic.Really how hard is it to control the people at your launches?

 

[sandman]

Whoa...wait a sec people...lets chill a bit.

We need to help with suggestions...nobody is trying to make this hard...we just don't want to be lax in our inspections by RSO's and we're looking for ways the committee can improve the situation.

It's not "aggravating" to be safe.

I agree that Rocsim data does not need to be presented but it should be verified by the builder before the launch.

Everyone is asking for strict rules to make things safer but they dont understand their going ot bite off more than they can chew and in the end it will make going to a launch painstaking cause of al the crap you would have to go through just to launch a rocket

Please...don't make a blanket statment like that...that's just argumentative and gets us nowhere.

Try to be constructive...not destuctive...that's how flame fests starts.

 

[BrnAgainRoc]

i wasnt trying to start a flamefest. And the things i said was walking a fine line bwteen truth and objective. We all want everyone to be safe and for our hobby to be safer. Thats the mission we're on.At the start people kept mentioning the RSO's being responsible for what the rockjet does and imo alone and maybe others agree i dont find that fair in my book.RSO's are to inspect rockets and to deem them safe.They cant be responsible period for what that rocket does after it leaves that pad. Now iam not saying that a RSO that has no clue to what he/she is doing by any means that person shouldnt be asked to perform RSO duties. Ive seen some RSO's being selected that really have no clue to whats going on.My main statement and point was the problems and accidents we are having most are accidents after the rocket has left the pad.We can build VERY safe rockets but once its up in the air its out of everyones control. We cant keep them from hitting cars or lawndarting the rocket, but we can protect all life on that field.And to do that everyone must pay attention to whats going on. I call them lurkers.Its mostly spectators that are there just to watch which theres nothing wrong with that but you can still make them obey the same rules that rocket fliers do. Now i also read about an accident investigation team. Thats fine and great but my concern isnt what happened to he rocket itself but everyones safety while and after it happened. When a rocket crashes usually we all know why it occured unless it was something completely out of the ordinary.I just think our main safety porblem that needs to be fixed is make people pay attention and adhere to our strict flying rules while on the field and allow no one to break them. If you see something being done wrong you need to point it out at that very moment and if they dont listen ask them to leave.

 

[Ted Cochran]

Originally posted by sandman


We need to help with suggestions...nobody is trying to make this hard...we just don't want to be lax in our inspections by RSO's and we're looking for ways the committee can improve the situation.

I'm still reading; keep the suggestions coming!

--tc
NAR69921

 

[BrnAgainRoc]

Ive sat and read over again for the 3rd time everyones suggestions and comments. I just dont think anyone is truly hitting the nail on the head. RSO's are still a huge concern but frankly a RSO cant do anymore than what they're doing now.As far as a NAR/TRA pressed Launch Rules i can understand and agree with.Iam not talking about the main rules we all follow when we are by ourselves in the middleof nowhere.Iam talking about the rules a Launch Host must use to prepare a site for a launch such as LDRS,etc etc etc. the launches were more than 3-4 people will be attending where there needs to be rules set for participants and spectators.

We all know rules with the RSO's but what about rules that effect everyone there even spectators.For example the normal guy there with kids just to watch launches and walking round looking at rockets and all the vendors.the people that are usually shuffling throuhg RMs motors at a vendor stand are usually the ones not paying attention to whats going on.or the mom andd aughter that got hungry and hot that decided to sit in their suv and eat their lunch and enjoy the air condition? these are the people that assume they dont need to follow the rules that we as fliers follow. IMO no one should be in a vehicle unless they're leaving the site.

Also i think having multple intercoms across the field which 2-3 would be good all depending on size of field ( i think it should be mandatory that large launches should all have some sort of communication system) which would make it easier for everyone to hear count downs and in case a rocket comes in balistic a fog horn over the intercom.This should get everyones attention and let it be known if that horn is heard then you need to be aware of whats happening and prepare to follow important instructions.

To discuss the cert program it seems fine the way it is.No matter how you tweek it or add to it, it wont do any significant change to how a person actually goes about certing. If we have the means and $$ we would all cert in a day. But usually the factor in certing is getting money together to complete that cert rocket.During that time we fly rockets and build others.I just dont see how this would make things any better.

I still think our main problem is awareness on the field. Spectators thinking they arent involved in whats going on when in reality they're a huge part of it.As far as property damage goes its unavoidable. When that rocket comes down you cant do anything about it what so ever. Just get everyone to safety and allow it to takes it course thats basically all you can do unless you're brave enough to pull out a blanket and try to catch it(was a joke).Ive seen rockets go through the RSO hands, pass the safety check, and then lawndart. I think anyone who is a constant flier has seen it at one point or another.We can examine the rocket all day or year long to figure out what went wrong. And ill be truthful with you, i dont care to much why the rocket lawndarted but i do care that bystandards could have been hurt in the process and in turn we did all we could to get everyone out of the way of the rocket. The rocket itself is the last thing on my mind.

 

[jflis]

One thing that may be missing (i've tried to keep up with this whole thread, but it's tough ) are "limitations"

We will not ever be *perfect* and the closer to perfect you get the harder the next percent improvement is going to be. At some point you get to the point of dimishing returns. Hard as that may be to swallow, there comes a point where the extra safety simply is not worth the trouble, cost, etc.

Until you build a dome to cover all spectators and modelers, that is impervious to a balistic rocket impact, you will never be 100%. No one will ever foot the bill for such a structure, so being 100% safe is clearly not worth the cost or trouble. I realize this is a lousy example, but you get my drift

How far away is far enough? The safety code says 15 feet for up to D motors. Is that perfect? Would not 20 feet be better? 50? 5000? 5000 would *clearly* be perfect as you won't get a D motor to go that far. Doesn't matter, 'taint worth it.

So, without being *dangerous* we need to acknowlege and accept that there will always be some risk. Let's do the right things to help reduce that risk, but within reason. It would also be helpful to have this explained to unknowing spectators in the form of a brief handout. This could include information about the NAR, TRIPOLI and the hosting club.

just some rambling thoughts.
jim

 

[prowlerguy]

This may be off the wall, but I was trying to think outside the box, so forgive me.

I know that all military/NASA launches have the ability to self-destruct if a guidance or other failure was noted by ground controllers. Is there some way we put a "univeral" failsafe on all models over a certain size (with kinetic energy being the parameter of concern) that allows the RSO to manually do something that would prevent a ballistic recovery?

 

[rbeckey]

Jim Flis has a point. I use the 80/20 rule for several kinds of projects at work. It states that 80% of the results will be gained with 20% of resource expenditure. (Resorces being mainly time, but money is also a resource to be considered.) Every percent of gain after that is increasingly expensive in terms of resource management, with the last few percent often being impossible with any reasonable expenditure.

The fact of the matter is that rocketry is supposed to be FUN. I do it to have a GOOD TIME. I ENJOY it. There is a certain amount of risk in any undertaking. Statistically you are in much greater danger driving to a launch than participating or watching. The rules we already have and basic common sense will take care of 95+% of problems. We have already far exceeded the 80/20 rule. The price of the last 5% will be the end of the hobby as it exists. If you suck away the last little bit of enjoyment for an unattainable goal, then what have you gained? We can require spectators to stand 500 yards away from low power pads, and it will be almost impossible for them to be injured. It will also be imossible for them to enjoy watching from that far away. Why bother if you can't hear, smell and for that matter, see what you came for? We could require the RSO to observe the building of cert rockets. We could make him test low power kits to failure point and then say "well, that one would have been strong enough to fly." What more can he do that won't verge on unreasonable, even rediculous, expenditure of time?

When my family goes out for rocket day, we generally expend approx. 40 motors, A-G. There has never been an injury. There have beem a few recovery failures, CATOs, and unexplained malfunctions. The observance of common sense rules has been sufficient to keep us safe. Perhaps a club needs more control over the process, but at this point the addition of more bureaucracy is not going to help.

 

[BrnAgainRoc]

I agree with the last 2 posts 100%. I posted before saying that you could only push the safety factor so far before it literally just makes flying rockets unpleasant. I believe if we work on our existing rules and find better ways of implementing them this hobby will be just as safe tomorrow as it is today.

 

[sandman]

Perhaps a club needs more control over the process, but at this point the addition of more bureaucracy is not going to help.

That sounds like a contradiction.

What I see coming out of the committee is a set of guidelines for better control of the process.

I guess if you want to you could call that "bureaucracy"...I'd call it "guidlines".

Po-tait-to....po-ta-to??

 

[rbeckey]

Sandman,
Bureaucracy is what happens at the DMV when you are trying to get them to correct an error they made.

That's what I don't want for club launches. People like me out here on our own will not be who sustains this hobby. People like me who come to a club launch and who feel like we're in the DMV won't be back. We can't afford that at this point.

 

[JStarStar]

I think for the most part, the existing rules and Safety Code are perfectly adequate, if they are actually followed.

And I think in some cases, RSO's have to be a bit more of a hard-arse about questionable designs.

And I also think there needs to be some reevaluation about how and why some rockets are being designed. We have more and more of the "Beavis factor," where people want to jam as many motors as possible together into an airframe, launch porta-johns, launch bowling balls, you name it -- whatever, as long as it makes a bigger fireball. Sure, you can do flashpan ignition and light hundreds of motors at the same time, but what about the ones you DON'T ignite?

Of course when these things are launched at Black Rock or the equivalent, that's one thing. I watch the show on Discovery about bowling-ball lofting, and I thought, "wow, that's cool, " just like everyone else. But is it really all that cool? Say a bowling-ball lofter breaks up at 5000 feet with a velocity of a couple hundred MPH, and that ball falls free. You don't want anybody or any thing under that ball when it comes down.

A bowling ball makes a free dive from a couple thousand feet and kills somebody, the news media won't care about the distinction between LPR and HPR.

 

[cjl]

I would have to say that bowling ball lofting is no more or less dangerous than a normal rocket - yes, it is 16lbs, but if a 16lb rocket (of any design) comes in ballistic, it will cause some damage - not just a bowling ball rocket. What do we do - limit rockets to 10lbs? Also, this is exactly why EVERYONE should be able to hear and respond to a heads up call - ANY rocket falling from the sky that weighs more than an ounce or two could injure someone - not just the big ones, and there should be a system where everyone can tell when and where a rocket is coming in hard.

 

[Hospital_Rocket]

Originally posted by sandman
That sounds like a contradiction.

What I see coming out of the committee is a set of guidelines for better control of the process.

I guess if you want to you could call that "bureaucracy"...I'd call it "guidlines".

What I am hoping for is a better distinction between the bneeds of model and high power rocketry. I do not believe the current HPR code has enough distinction to make it truly effective. I get the sense that it's genesis was in the, probably sudden, appearance of composite and other high performance motors in a world where a D was a big nonking moyor.

The rate at which speed, thrust, complexity, and durability of rockets have evolved merit a somewhat different stance than modroc. Both should have saftey principles grounded in the same ideas. MPR & HPR need some different, and possibly more stringent rules.

No, I don't want a bureaucratic conga line to launch, however I do think that we owe it to each other to make sure when we apply current to the igniter, we have the tools to make sure we have made a good-faith effort to make sure that the only thing that happens is what we planned on.

The creation of those tools is where I hope Bunny, Jay, and the rest of the BOD are headed.

A

 

[GL-P]

I'll put my thought concisely:

1) RSOs should have a checklist:

-fins
-bend lenghtwise?
-chute size (maybe a chart with weights to give general chute sizes need for a given weight)
-motor assembly (questions about if it was first RMS, CTI, etc.)
-recovery assembly (ask that quicklinks attached, etc., I've actually seen ppl forget this)
-stability (VCP?, ROCKSIM?, etc)

etc...

This is just short list. There will always be exceptions as jflis (the foam cup rocket expert) pointed out!

2) Alarms should be mandatory. Every hpr launch I've been to has some sort of a loudspeaker and/or alarm to grab ppl's attention. They really work!

3) Some distances could(should?) be extended a little more (by 20ft?) MIGHT help.

4) Pad managers should check angle of launch rod. No pointing a rocket over the flight line!!!

5) Classes on motor assembly! Classes could be organized for reloadable motors in the MPR class to teach basics! Hands on with an expert. Questions about the instructions can be answered! All that it should cost is a motor. Make it a volunteer event once at large launches. Make it fun!!!!!

6) The first cert flight could have a mandatory hands on course the morning of the flight. Teach good values! Bring your own rocket. Buy the motor. Make the motor assembly part of the class. Teach some values! Get them started on good values!

This is a brain dump. Some ideas I don't like, some I do. Just some ideas. More likely to come...

 

[Zachary Lau]

Originally posted by cjl
and there should be a system where everyone can tell when and where a rocket is coming in hard.

I'd suggest an alphanumeric grid square system. Make a map of your launch site and draw a grid over it--label one axis alphabetically and the other numerically--just like bingo--b9, c6, a3... are quick and easy to convey to a large crowd.

 

[LaneKG]

I would like try having people who have a track on a rocket to point at the rocket with one hand Then if it is is incoming they can yell out and motion the affected party to move out of the way with their other hand. If you don't see it it is impossible to know what to do.

Anybody doing this?

Thanks,

Greg

 

[wwattles]

Greg,

That's exactly what we do at our launches currently.

Zach, the problem with your idea is that we tend to move around a lot at our launches, talking with other folks, looking at rockets, going to and from the pads, and recovering rockets (and stray kids and pets). You won't always know what grid you are in. Good idea, but too cumbersome to put into effect.

For the larger launches, we designate areas (West end, East end) and if we can tell how far back the rocket will land behind the line, we'll announce that as well.

WW

 

[Ted Cochran]

Originally posted by LaneKG
I would like try having people who have a track on a rocket to point at the rocket with one hand Then if it is is incoming they can yell out and motion the affected party to move out of the way with their other hand. If you don't see it it is impossible to know what to do.

Anybody doing this?

Yes! That's a great practice! It's very easy to figure out if you're in danger--all the people around you are pointing over your head!

The other thing folks have to learn to do is not move until/unless necessary. You might only have to take one step to the side to get out of the way; you might as well give your visual system all the time it needs to figure out which direction to step in

--tc

 

[teflonrocketry1]

Jim,

If you were the RSO and were given simulation data that idicates a ballistic mode of recovery (e.g. no ejection charge) in a particular model (e.g. 8lb bowling ball loft) will put the flight on top of the RSO table with 90% accuracy, would you push the launch button? You can get wRASP simulations to about 80 to 90% accuracy and RockSim to about 90 to 95% accuracy. Wouldn't it be better to have this data? You can calculate where a model will land with a certain probability (Splash software), if the 90 percent confidence level of the location of the landing is the spectator or parking area, then maybe the flight shouldn't be made, regardless of the program used to simulate this. Maybe its time we all did some simulations to make the launches and participants (not necessarily the rockets flight) safer. Have you ever looked at the ballistic recovery of a flight using simulation software, I think most people ignore these worst case senarios.

RockSim is currently best program for doing these kinds of simulations because it does a great job at taking into account the effects of wind and dynamic changes that occurr during flight. You can get a lot of landing information about a model that is complicated and otherwise difficult to simulate just by entering its frontal diameter average weight and average length and fin area into a program like wRASP. I do this all the time to check the results of complicated design simulations, may be this kind of approximation is all that would be required.

Bruce S. Levison, NAR #69055

 

[jflis]

Originally posted by teflonrocketry1
Jim,

If you were the RSO and were given simulation data that idicates a ballistic mode of recovery (e.g. no ejection charge) in a particular model (e.g. 8lb bowling ball loft) will put the flight on top of the RSO table with 90% accuracy, would you push the launch button?

Bruce S. Levison, NAR #69055

Bruce, not sure if I am the "jim" you addressed this to, but I wanted to reply anyway.

To answer your question, with that data, no I would not push the launch button and would recommend that it not be pushed until we were able to change the simulation (perhaps all that would be needed would be to tilt the launch pad the other way).

Now, on the other hand (I am going to switch this conversation to *model* rocketry as I am not qualified to comment on HPR activities and fully admit this), if someone came up to the RSO table with (for example) a scratch built D powered model and showed me no simulations I would not sumarily reject the flight.

Also, regarding software to determine the landing point. I have to assume that the angle of the launch rod/rail is part of the simulation. If the landing is in an undesireable location, you simply tilt the pad differently. No changes to the "rocket" are made at all.

Lasty, your question "wouldn't it be better to have this data?". Yes, but that doesn't mean it should be required.

my 2 cents
jim

 

[teflonrocketry1]

Jim,

You were the right Jim I was addressing these comments to!

Yes you could simply change the lauch rod angle to remedy these situations, but my point is no one even bothers to look at simple things like this before hand. Maybe the RSO should have this software or minimally some typical flight path charts at every NAR launch. It is my opinion the only way to bring a higher level of safety to launches is to conduct more and relevant flight simualtions before the event and to review these for each flight just before the launch.

Bruce S. Levison, NAR #69055

 

[cls]

because we have no hard data on flight failures, it is not at all clear that the majority of issues occur during boost - I'd bet most issues are recovery related, not boost stability related. so, I don't think that simulations will really help that much.

I'd trust my sims, I'd trust your sims Bruce, but generally not anyone else's - a million things could be wrong in the sim. RSO's job is final systems and sanity check, not deep QA.

my long way of saying, I hope the committee report says something like "all NAR sections report flight result data for 1 year". then we can see x% of flights were successful, x% had recovery issues, x% had boost stability issues, x% had build quality issues.

 

[rbeckey]

Bruce,
I don't believe that requiring a simulation for every rocket flown is practical or even a fair test. I am certain that there are many people who build much better rockets than simulations. It brings up a situation where people can be denied (or approved for!) flight because of a possibly faulty simulation instead of an inspection of the actual rocket. To be accurate to the degree needed, the simulation will have to be done on site at the time of the flight, assuming that somebody had the foresight to bring a thermometer, anemometer and barometer to the launch. Then somebody will have to check the math. Perhaps the RSO? After all, he has nothing better to do. Perhaps require laptops at the launch for this purpose, say, one for every three pads? Most clubs could probably afford that, right? To be honest, I don't know offhand or even care about the frontal diameter or fin area of even one rocket in my fleet. Weight would be easy to figure with a postal scale, but I don't lug one of those around, and I don't intend to start. As far as wind speed and direction, at my usual launch site it is variable enough at different model and mid power altitudes that any simulation would be far less than 80% accurate. That is why I fly a 3FNC tester at the start of every launch, and I still manage to get one in the trees now and again. I do simulate scratch builds in RockSim, and so far my simulations have been 95+% accurate as far as motor selection and stability. Landing them out of the trees is another matter. By the way, I have v 6.05. Would I be required to acquire version 8?

The idea is to attract and keep interested people in the hobby. I personally don't see how this is going to help. For the kids especially, it is hard enought just to build a decent rocket. Now you want them to buy or at least "borrow" simulation software and become expert in its use, or learn to do the math. It would be the same as taking the rocket off them and telling them to go home and play Nintendo like the other kids.

If you want to make that kind of mathematical acrobatics apart of a level two or three cert, I guess it doesn't matter to me because unless I hit the lottery, it will never affect me directly. I am betting that the chilling affect of requiring it for every high power flight will eventually trickle down with the same or greater consequenses as the isolated and improbable tragic accidents that are sought to be prevented. Making it part of low and mid power is completely over the top, in my opinion.